1. Field of the Invention
The invention relates to a filter capsule with a filter housing which, on at least one end face, has an end cap with an air release valve.
2. Description of the Related Art
Plastic filter capsules suitable for disposal after one use are employed increasingly in biotechnology. More particularly, increasing use is being made of filter capsules with the inflow and outflow configured in a T-style design. Thus, the housing inlet and outlet are arranged on one end, or on one end cap, of the filter capsule. The housing inlet and the housing outlet, in this case, are designed in a T-shape so that they each are arranged transverse to the longitudinal axis of the filter housing and are connected at an angle to the non-filtrate chamber and filtrate chamber, respectively.
An air release valve is required to avoid a gas volume developing at the upper end of the non-filtrate chamber if the two connection pieces are arranged in the vertical direction on the upper end cap of the filter capsule. A corresponding air release valve is required on that end cap opposite the end cap with the connection pieces if the filter capsule is used so that the end cap carrying the connection pieces is at the bottom in the vertical direction.
Air release valves that are at the highest point disadvantageously protrude beyond the wall of the filter capsule or end cap in the direction of the longitudinal axis or occasionally transverse to the longitudinal axis. These air release valves, particularly those of plastic filter capsules, are susceptible to breaking off if used improperly. Filter capsules may be welded into a film to achieve a sterile state. However, the packaging film may be damaged by the air release valve and incorrect storage. As a result, the filter capsule may become contaminated.
JP 2003210912 A discloses a filter capsule that has a cylindrical filter housing with upper and lower end faces closed respectively by upper and lower end caps. The upper end cap has an air release nozzle connected to a non-filtrate chamber arranged between a filter and the housing wall. The lower end cap is opposite the upper end cap and has a housing inlet and a housing outlet arranged transverse to the longitudinal axis of the housing. The housing inlet and outlet form a T-shape to define a T-style design. The housing inlet is connected to the non-filtrate chamber, and the housing outlet is connected to the filtrate chamber. The lower end cap likewise has an air release nozzle connected to the non-filtrate chamber. Depending on the installation position, the lower air release nozzle in each case is closed, and the air release nozzle arranged at the top in the vertical direction is used. Air release valves, not shown, can be attached to the air release nozzles.
The air release nozzles or air release valves connected to the air release nozzles of the known filter capsule disadvantageously protrude beyond the end caps in the longitudinal direction and can break off if used improperly. It is also possible that any outer packaging will be damaged by the air release nozzles or by the valves thereof.
Accordingly, an object of the invention is to provide a filter capsule with air release valves that are not susceptible to breaking off the end caps, even in the event of improper use, and that cannot adversely damage any outer packaging.